1. Field of the Invention
The present invention relates to a method for fabricating solar lenses, particularly to a multi-cavity injection-molding method for fabricating solar lenses.
2. Description of the Related Art
Various substitute energies have been developed to confront the problem of exhausting fossil fuels, including solar power, wind power, hydraulic power, geothermal power, etc. Because solar energy is stable environment-friendly, eternally-sustainable and spread everywhere, it has been one of the most promising substitute energies. There have been various schemes to harness solar energy, including a light-concentration solar cell that can converts solar energy into electric energy.
A light-concentration solar cell includes a group of solar chips and a group of solar lenses arranged above the solar chips. The solar lens is a Fresnel lens able to focus sunlight on the solar chip, whereby is increased the power-generation efficiency.
The conventional Fresnel lenses for solar cells are fabricated with a four-cavity injection mold. The conventional technology is hard to control the molding conditions and has problems of uneven stress and thickness. Further, the Fresnel lens fabricated with the conventional technology is fragile and likely to deteriorate and have scratches.
In another conventional technology, a Fresnel lens is made of an acrylic material and stuck to a glass surface with adhesive. However, the conventional technology has the following disadvantages:    1. Sticking lenses is time-consuming and likely to generate bubbles.    2. The positions of lenses are hard to control.    3. As the position of a lens is hard to accurately control, the position of the solar chip below the lens needs to be adjusted. Adjusting solar chips are also time-consuming.    4. After the lenses have been stuck to a piece of glass, they need baking. Thus, the fabrication process takes too much time.
Accordingly, the present invention proposes a multi-cavity injection molding method for fabricating solar lenses to solve the above-mentioned problems.